1. Field of the Invention
This invention relates to an equipment (apparatus) for adjusting the shape of a running band-like or plate-like metal material in the width direction thereof and especially relates to a target shape adjusting equipment for metal materials for adjusting the shape of a running band-like or plate-like metal material in the width direction thereof after a specified treatment has been given, by giving target shape data to a shape controlling section.
2. Description of the Prior Art
A reduction roll mill 2 for rolling aluminum foil, which is one of the examples showing the background of the invention is shown in FIG. 22.
In aluminum foil rolling, material aluminum foil 51, 700 through 1700 mm wide and several micron meters (.mu.m) through several hundred micron meters (.mu.m) thick, which is wound on the incoming side coil 50 is rolled by a pair of reduction rolls 52 at a speed of about 300 through 1,200 meters per minute, thereby causing the thickness thereof to be reduced to about one-half to one-third. The rolled aluminum foil 53 is transferred in the direction of an arrow K by a constant tension produced by rotary drive of a drive shaft at the outgoing side coil 64 (FIG. 1) and is accordingly wound on the outgoing side coil 64. For example, when aluminum foil 51, several hundred micron meters (.mu.m) thick, is finally rolled to form aluminum foil 53, several micron meters (.mu.m) thick, the rolling process is to be repeated several times, and the number of rolling times is called "number of pass times".
In such a metal rolling as described above, there remarkably exist an "elongated portion" and a "tightened' portion in the width direction (an arrow "L") of foil although the thickness of the aluminum foil 53 is the same as shown in FIG. 23. Namely, the elongated portion 54 forms mountain parts 56 and valley parts 57 along with the direction (an arrow "K") of transfer of the aluminum foil 53, and the tightened portion 55 is generally of plain shape. Therefore, the aluminum foil 53 shown in the figure is elongated at the central part of foil in the width direction thereof (an arrow "L") and is tightened at the end parts thereof.
Such distribution of elongated parts and tightened parts of foil in the width direction thereof (an arrow "L") as shown in the above is hereinafter called "surface shape" or "actual shape" of the aluminum foil 53. The surface shape or actual shape will greatly influence the quality of foil products. In some cases, a great tension may be given to the tightened parts 55 to cause the foil to be broken down, and the elongated parts 54 may cause wrinkles to be present. Naturally, an even or flat shape on which elongated and tightened portions are uniformly produced is desirable as the final product for aluminum foil 53. However, the actual shape is not necessarily even or flat per pass. The shape of aluminum foil 53 which exists in the passes on the way is diversified.
The surface shape of aluminum foil 53 shown in the above can be controlled by changing the shape of reduction rolls 52. As shown from FIG. 22 through FIG. 24, the reduction rolls 52 produce an expansion so-called "heat crown", resulting from heat generation in rolling and heat transmission characteristics thereof. The example shown in FIG. 24a-24c is the case that the quarter portion "a" is expanded. Such an expansion, i.e., heat crown may change the surface shape of aluminum foil 53 according to the position of appearance and the degree of expansion. Namely, aluminum foil 53 which is rolled by the portion in which the degree of expansion of the heat crown in the reduction rolls 52 is large is caused to be elongated. Therefore, the surface shape of the aluminum foil 53 can be controlled by changing the temperature or the amount of coolant 58 (FIG. 1) jetted toward the reduction rolls 52 to cool down the reduction rolls 52 in the width direction (an arrow "L" in FIG. 23) of the aluminum foil 53.
Such a shape control of aluminum foil 53, what is called a flatness control, is conducted by the shape controlling section 3 adjacent to the reduction roll mill 2. Namely, the actual shape data of elongation and tension of the aluminum foil 53 is inputted in the shape controlling section 3 from an inspection roll 4 consisting of thirty-six (36) elements 4e which are divided in the width direction and being rotatably mounted at the outgoing side of the reduction rolls 52. Each of the elements 4e is furnished with one piezoelectric element (not shown) which can function as a sensor for detecting contact pressure operating on the outer periphery of the elements 4e.
In the aluminum foil 53 which is pushed toward the elements 4e and is pulled with a constant tension in the direction of transfer (an arrow "K"), the contact pressure between the elongated portion 54 thereof and the elements 4e is detected to be small when the elongated portion 54 passes on the elements 4e. On the contrary, the contact pressure therebetween is detected to be large when the tightened portion 55 passes thereon.
Hereupon, as shown in FIG. 24, the actual shape of the aluminum foil 53 is expressed as distribution (actual shape data) in the width direction of the elongation ratio obtained by converting the contact pressure data detected by respective elements 4e. In the case of the illustrated example, the target shape is so set that, as the quarter portion "a" of the reduction rolls 52 is expanded too much, cooling the quarter portion "a" may be promoted and heat may be accumulated at the central portion of the reduction rolls 52 and at both the ends thereof.
The shape controlling section 3 compares the actual shape data with the pre-inputted target shape data and operates the result thereof, and the shape controlling section 3 can increase the coolant 58 to be jetted toward the portions of the reduction rolls 52 corresponding to the elements 4e at which the actual shape data shows higher elongation ratio. The coolant 58 is jetted from jetting tubes 59 which are provided at the incoming side of the reduction rolls 52 and which are separated for jetting in the foil width direction (an arrow "L").
Thereby the heat crown of the reduction rolls 52 is lightened to cause the portion of aluminum foil 53 corresponding to the quarter portion "a" to be deformed toward a state of tension. And in the case that the elongation ratio is lower in the actual shape data, inversed operation is to be conducted. Also, in the target shape data, the elongation ratio obtained from the elements 4e corresponding to the quarter portion "a" is frequently so set to zero (0) so that cooling the quarter portion "a" of the reduction rolls 52 can be promoted.
Here, the actual shape data may be the value outputted from the sensor or may be of such a concept as to express the shape of elongation and/or tension which is shown in the following example of the preferred embodiment.
As described in the above, in foil rolling, a final product can be obtained by repeating rolling (passes) several times. Such a plan as for securing a final product by determining how thin the thickness of the foil or how the surface shape thereof is made at the "n"th pass is called "Direction of the operation". This direction of the operation defines the target shape of elongation and tension in the passes on the way together with the target in thickness, in order to finish the final products to an even and flat shape of uniform elongation and tension.
The distribution of elongation and tension is passes on the way as shown in the above may differ in the actual operation. This is because operation conditions such as deformation (heat crown) due to heat on the reduction rolls is different on respective passes. For this reason, the direction of the operation defines the target shape of elongation and tension in each of the passes, taking somewhat predictable operation conditions into consideration, in the actual operation conditions thus described above.
However, such a target shape of elongation and tension as in the direction of the operation may not be often in accord with the actual target shape of elongation and tension by the shape controlling section 3, i.e., the target shape data. For instance, there is a case that a good result has been accomplished by so setting the target shape data to be set in the shape controlling section 3 as shown with a solid line in FIG. 25 when rolling a certain material by a reduction roll mill at a certain pass, aiming at the target shape on the direction of the operation as shown with a dashed line in FIG. 25.
Thus, the reason why the target shape on the direction of the operation is not in accord with the target shape in the actual controlling is that even though the coolant amount for the reduction rolls 52 is divided and adjusted in correspondence with the elements 4e of the inspection roll 4 the heat crown shifts due to the heat transmission of the reduction rolls and the shifting pattern thereof may change from time to time according to such operation conditions as the kind of a metal material, the surface shape of the above reduction rolls, heat balance, temperature, rolling speed and foil base shape. Influences by the operation conditions and the kind of materials as shown in the above can seldom be expressed with any mathematical model. It belongs to skill or engineering know-how. Therefore, the target shape data must be adjusted, corresponding to various kinds of actual shape which may appear on the way of respective passes, in order to approach the direction of the operation as much as possible.
For this reason, in the conventional controlling equipment for foil rolling and other metal rolling, it has not been possible to automatically set the target shape data in each of the passes. It depends upon the senses of skilled operators having rich experiences in this field. Therefore, such a conventional system has not been suitable for producing aluminum foil along with the ideal direction of the operation by securing timely and accurate control.
Also the shape judgement of the actual shape which is reflected on the target shape as shown in the above depends upon the visual judgement of an operator 5 since before, and it is not convenient on the current shape management and control, judging from such human error factors as personal differences, other difference in the skill accomplishment, etc.
Also, in the above reduction roll mill 2, it has a large meaning in controlling the process that not only large and small sizes of the actual shape data pertaining to the elongation ratio from individual elements 4e of the inspection roll 4 but also the whole patterns of the surface shape, i.e., shape conditions and the degree thereof are judged. However, according to the conventional manner of detecting the shape, as it has depended upon the experiences and senses of operators that the whole pattern of the surface shape is judged, it needs skills and has only less suitability.
And in such a reduction roll mill 2 as shown in the above, the surface shape of aluminum foil 53 may change with a constant tendency maintained even though aluminum foil is rolled under the same condition. For instance, as both the ends of the reduction rolls 52 are getting heated, an expansion portion "a" called "heat crown" appears at both the ends of the reduction rolls 2 as shown in FIG. 24 and the degree of the expansion may be gradually increased. Therefore, the surface shape of the aluminum foil 53 is apt to be elongated at the end portion thereof.
The tendency in change of the surface shape thus described in the above is as shown in Table 1.
TABLE 1 ______________________________________ Item Tendency in change of the shape ______________________________________ (1) The end portions of aluminum foil are apt to be tightened. (2) The end portions of aluminum foil are apt to be elongated. (3) The elongation and tension of the end portions of aluminum foil are cyclically changed. (4) The foil condition is constant and stabilized. ______________________________________
For example, when the current surface shape is specified as "end elongation" and the degree thereof is in the level 3, the method of adjusting the target shape to be matched in future in the tendency described in the item (1) in Table 1 must be different from that in the tendency did in the item (2). In the case of the tendency shown in the item (3), it is necessary to decrease the control gain on setting the target shape data given to the shape controlling section 3 which controls the surface shape.
On the other hand, there is a case that all the rolling conditions can not be expressed only by the actual shape data at this moment and the tendency in change of the shape led out by the operation from the actual shape data. That is, unless the data is sampled periodically and the actual shape data at several kinds of time in the past is used, there exist many statistical characteristics informations which can not be obtained, such as, for instance, the tendency in change of the sampled data described in the above, average, dispersion, correlation between data, three-dimensional pattern recognition, etc.. And such a statistical characteristics information as thus shown is important for adjusting the surface shape of aluminum foil 53.
Thus, the target shape must be changed according to the operation conditions or the actual shape which may change from time to time.
However, as for the target shape data, the judgement for the necessity of changing the target shape for when to change the target shape and starting the action to change and to adjust the target shape depend upon an operator 5. Therefore, automatic action for changing and adjusting the target shape was not possible. For this reason, it was not possible to adjust the target shape so that it can be properly and timely changed, following the operation conditions of aluminum foil rolling which may minutely change.
Furthermore, in the case that both the judgement for the necessity of change of the target shape and the starting of adjustment of the target shape change are automatically carried out through judgement by utilization of the threshold values for the actually detected shape data, the actual shape data is processed as binary logic of 1 and 0 after having judged the threshold value. Therefore, it was impossible to minutely grasp the degree of abnormality of the actual shape. For example, it was not possible to make such a judgement as for starting the adjusting action even though the actual shape data pertaining to a certain state "A" partitioning to the actual shape even slightly exceeds the threshold value when both the above state "A" and another state "B" are abnormal at the same time without starting the above adjusting action if the actual shape data slightly exceed the threshold value when only a state "A" is abnormal.
As described in the above, in the case that only the latest actual shape data is used although both the past statistical characteristics information pertaining to the actual shape data of aluminum foil 53 and the so-called latest actual shape data at the moment are important, it can not be said that it is enough to judge the necessity for changing the above target shape.
On the other hand, the inference rule on the basis of the knowledge obtained through the experiences of a skilled operator, that is, the inference processing on the basis of the inference rule in which the condition section is regarded as the above actual shape state and the conclusion section is regarded as action corresponding to the above state can apply to the target shape adjusting equipment of the band-like or plate-like metal material which is running. However, in this case, when it is judged that the actual shape of aluminum foil 53 which is produced by the control of the reduction roll mill 2 reverts to two or more various kinds of states, respective action options corresponding to each of the above states are selected. If there occurs a case that contradiction may be brought in the contents among the corresponding actions, the inference rules furnished with respective actions are competed each other, thereby causing a proper action not be determined.
In the case that the actions having the same content are selected at the same time, corresponding to each of the above states according to the results of having judged that the above actual shape reverts to a plurality of states as well as in the above, such a problem as redundancy on execution of the actions may occur, thereby causing an action having the same content which intends to change the above states to be performed subsequently or at the same time.
Additionally, in the case it is judged that the actual shape of aluminum foil reverts to a certain state, there may exist a plurality of actions corresponding to the corresponding state. Unless the operation condition is changed as the algorithm for selecting a single or a plurality of actions among these actions is executed according to the operation conditions described in the above, the corresponding action is repeatedly selected and executed even in the case that the selected action takes no effect on the actual shape state of the aluminum foil 53.
Under such conditions as shown in the above, even in the case that the contradiction among the actions shown in the above and/or the redundancy are dissolved and a proper action is determined, the action is not necessarily effective for the states of the aluminum foil 53.